The video is, indeed, impressive - but it could also give a false impression. The transistor operating spec. is 100us pulses at 20% duty cycle - 100us on, 400us off. Looking at the current drawn duri
Yes, there's no doubting that these modern FETs are generally quite robust. For most amplifiers there's a range of phases of high VSWR where they will survive ok, and a smaller range where they are m
My first reaction would be to agree with you, but researching PSUs for a quote the Vicor 4kW Megapak was in the frame - that uses passive inductive correction on a rectifier/capacitor input system an
I need to start clearing some stuff, these came off the shelf first. 2 pcs Comet CV1C-1000L/25 30-1000pF 25kV test 15kV working. I have a datasheet which shows current capability up to 106A. 7"/180mm
Likewise in the UK. It's unusual for any individual house to have three phase as standard, single phase plus N is normal but the distribution network is three phase plus neutral. Steve Jim, you will
I imagine the bias circuit is probably active with a filtered and decoupled reference so ripple on the raw input will be taken out. Another option is that it's brute force biassing with a diode (or C
I'll echo other's comments about Arctic Silver, which I've used on numerous high power transistor amps. Taking for granted that the copper heatspreader and main heatsink are milled truly flat, the cr
One word of caution with Manfred's technique - be very careful if applying clamping pressure onto a transistor with a ceramic cap. The cap is strong round the outside edge, but weak in the centre. If
the crucial thing is to get the transistor flange flat as well. The majority I've handled are not anywhere near flat, and always bowed upwards in the centre (something that hasn't improved since the
The flanges on the common four lead transistors with round caps are soft copper, and bend as you say. When the screws are tightened, metal is displaced inwards and the large central patch tends to li
I opened and photographed a dead one a while ago. The pictures are here: http://gs35b.com/gs35b/bang.html Would the drift happen if a tiny bit of cathode material evaporated and migrated to the grid?
The tube was one offered to me for the cost of postage, I don't know its history. It showed no signs of life and high hipot leakage so I opened it up. I think the photos were taken with my first digi
I had the same when buying a bunch of 300W parts a while ago. I was told it's to do with the tape/reel packaging they come in and doesn't affect the electrical spec. Steve Gentlemen, I found somethin
I'd say you were right first time - 8877 has a heater (to heat up the cathode), 3-500Z has a filament, like a light bulb. Steve _______________________________________________ Amps mailing list Amps@
It can sometimes take a couple of goes to get Ben's attention. His copies of manuals are high quality, nicely bound etc. - but not cheap. Steve Yahoo is your friend http://www.benduncanresearch.com/m
For class AB amplifiers I have a rule of thumb (which got named after me at one place I worked) - for output powers from 10% to P1dB device dissipation is roughly constant. Tx/rx duty cycle - we used
The bulk of the datasheet appears to be identical to MRF6VP41KH, apart from being described as suitable for "communications, radar and industrial applications" as opposed to "industrial, medical and
Make sure your transformer is up to it - big caps can mean higher peak currents and more I^2xR in the windings. Steve cheap on the surplus market as well. IMO, 1% ripple is the minimum that you shoul
Make sure your transformer is up to it - big caps can mean higher peak currents and more I^2xR in the windings. Steve values used. In actual usage, there is no issue.....provided the xfmr is the low
Don't assume that the meter reading can be trusted - don't rely on any carbon resistor in there to be the right value. Steve I have what I consider to be a strange problem with my MLA 2500. First, I